Electric switch



Dec. 20, 1927.

C. CHRISTENSEN ET AL ELECTRIC SWITCH Filed March 13., 1925 aww fuw rs eon n .Len r 0 e t FM m n .m I H p i h v T w h C /////lllllll PatentedDec. 20, 1927.

,RATIIGN OF 'NEW YORK.

insane ts'WITCI-li.

Application filed Ii larch i3, 19%.

Our invention relates to electric switches of the oil break type such asare used to control high potential circuits and which comprise a set ofmain switch contacts for normally carrying the load current and set ofauxiliary explosion chamber contacts for making the final break of thecircuit.

One object of our invention is to provide an arrangement in which animpedance is included in the connection between the mainv and itsauxiliary star 1: contacts.

Another objectis to provide for supporting the two sets of com-acts inthe same oil tank in a manner to facilitate the introduc tion of thedesired impedance between the aforesaid contacts.

A further object is to provide arrangement of main and auxiliary switchcontacts whereby the gas produced by the one set of contacts shall notinterfere with the proper functioning of the other set.

Our invention will be better understood by reference to the accompanyingspecification and drawing and its scope will be pointed out in theappended claims.

Figure l is a view illustrating our invention, partsv being broken awayto more clearly show the construction.

Fig. 2 is a transverse sectional view of the same taken on the line 2-2of Fig. 1.

Referring now to the drawing, an oil pot 1 having an insulating lining 2and containing a quantity of oil 3 has a cover a carrying all of theswitch terminals which are removable therewith. Two insulator bushings5, 5 carry conductors 6, 6 and are mounted in diametrically oppositeopenings in the cover, suitable clamping rings 7 being provided tosecure them in a vertical position. Each conductor 6 connects with aterminal 8 having a main contact 9 and an arcing contact 10. The movablemember of the switchcomprises a bridging member having a pair of arms 11extending in opposite directions from the center operating rod 12 and asecond pair of arms 13 also extending in opposite directions from theoperating rod 12 but atright angles to the arms 11. At the extremitiesof the arms 11 suitable contact plates i l and 15 are provided forengagement with the main and arcing contacts 9 and 10 respectively. Theparts thus described constitute what may be termed the main switch andmay be designed to provide whatever current carrying capacity is deeded;

in orde" that the switch may be employed to interri i iigi tensionch-cuiis particu larly under circuit conditions without the oil throwingdisadvantage connnon to such switches we have provided an auxiliary s'tch of the e' 'plosion chamber type, which switch is connected. inparallel relation to the main switch, the construction being such thatthe a. switch is opened subse quently to inain switch. At diametri"cally opposi..= points and equally distant from the insulator bushings5, 5, a pair of small insulators l6 and 17 are secured to the under sideof the cover l by clamps 18. Each of these insulators, one of which isshown in partial section in Fig. 1 carries an inverted cup 19 having acover 90 and forming an explosion chamber 21. A stationary contact 22 inthis chamber is sup ported by a tube threaded into the base ofthe-inverted cup 1.9, the contact 22 being adapted to receive the rodconstituting the mo *ablecontact of this switch. The rous 2 1 arecarried by the arms 13 and are of such length that the circuit betweenthem and the stationary contacts is not broken until after the circuitis broken at its main switch. For placing the auxiliary switch inparallel relation to the main switch each stationary contact 22 iselectrically connect ed with one of the terminals 8 of the main switch.This connection comprises straps 25 and 26 which are preferably ofresistance material. However, under certain circumstances it may befound desirable to employ a reactance instead of a resistance or even apair of conducting bars of negligible resistance. The arrangement of thestationary switch terminals at the four corners of an imaginary squarehas, aside from struc tural advantages, the advantage that the main andauxiliary switch contacts are separated laterally a considerabledistance which enables the contacts of the main switch to open withoutthe possible interference of the gas therefrom with the auxiliary switchand permitting the latter switch to utilize fresh quantities of oil.This arrangement is also especially adapted for the conductiveconnection between the main and the auxiliary switch terminals.

In the operation of the switch, assuming the parts to be in closedcircuit position, the initial downward movement of the operating rod 12carries with it the bridging member and the arms 11 thereof first breakcontact with the terminals 8 of the main switch. There still remains acircuit connection be tween the terminals 8 through the auxiliary switchand the straps and 26. Upon further downward movement oi the operatingrod, the movable contact rods 24 of the auxiliary switch break theremaining shunt cir cuit in the explosion chambers 21.

It is well known that the presence of inductive loads makes it moredifficult to break the circuit thereof. Since the tangent of the angleof lag is an inverse function of the resistance in the circuit it w illbe obvious that the additional resistance of the straps 25 and 26 whendirectly included in the circuit will exercise a beneficial eiiect uponthe circuit by improving the power factor, there by facilitating thefinal breaking of the circuit by the auxiliary switch,

lVhile we have described only one embodiment of our invention, we do notwish to be limited to the particular form shown and described as it willbe apparent that many modifications therein may be made withoutdeparting from the scope of our invention as set forth in the appendedclaims.

hat we claim as new and desire to secure by Letters Patent of the UnitedSi ates, is:

1. An electric switch comprising a rccep tacle having a cover and:ulapted to contain an insulating liquid, insulator bushings mounted inthe cover, fixed contacts carried thereby, insulators depending from thecover and spaced laterally on opposite sides of .a line joining saidinsulator bushings,

an explosion chamber containing a fixed auxiliary contact supported byeach insulator, impedance connecting each fixed main contact with aseparate fixed auxiliary contact, a movable bridging member having maincontacts for engaging the fixed main contacts and having laterallyextending arms carrying movable auxiliary contacts, said latter contactsbeing arranged to disengage the fixed auxiliary contacts in theexplosion chambers subsequently to the disengagement of the maincontacts and said impedances being arranged in the receptacle beneaththe liquid level.

2. An electric switch comprising a receptacle having a cover and adaptedto contain an insulating liquid, insulator bushings mounted in thecover, fixed contacts carried thereby, insulators depending from thecover and spaced laterally on opposite sides of a line joining saidbushings and at equal distances from the bushings, an explosion chambercontaii'iing a fixed auxiliary contact supported by each insulator, animpedance connecting each fixed main contact with a separate fixedauxiliary contact, a movable bride-ingmember having main contacts for'ing the fixed contacts and having arms sliding laterally from oppositeside thereot carrying movable auxiliary contacts, said latter contactsbeing arranged to disengage the fixed auxiliary contacts in theexplosion chamber subsequently to thedisengagement of the main contacts.

In Witness whereof, CHRISTEN Crnnsrnm sm: has hereunto set his hand this2nd day of March, 1923, and PHILIP G. LANGLEY has hereunto set his handthis 8th day of March,

CHRISTEN CHRISTENSEN. PHILIP G. LANGLEY.

v Certificate of Correction. Patent No. 1,653,086. Granted December 20,1927, to CHRISTEN CHRISTENSEN ET AL.

It is hereby certified that error appears in the printed specificationof the abovenumbered patent requiring correction as follows: Page 2,line 70, claim 2, for the Word side read sides; and that the saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent ()flice.

Signed and sealed this 17th day of January, A. D. 1928.

[SEAL] M: J. lVIJORE Acting gommissioner of Patents.

Certificate of Correction Patent No. 1,653,086. Granted December 20,L927, to CHRISTEN CHRISTENSEN ET AL.

It is hereby certified that error appears in the printed specificationof the abovenumbered patent requiring correction as follows: Page 2,line 70, claim 2, for the Word side read sides; and that the saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent Oflice.

Signed and sealed this 17th day of January, A D. 1928.

[SEAL] M; J. MOORE,

. Acting Commissioner of Patents.

